U.S. Pat. Nos. 1,315,196, Moorehous; 2,416,400, Thomas; 2,882,633, Howell; 3,310,901, Sarkisian; and 4,145,828, Hillstrom, disclose picture and poster frames which include elongated metal strips hinged along one edge at the periphery of the frame and biasing springs engaging the strips to hold the same in either an outwardly extending, open position permitting the display material to be inserted into or removed from the frame and a closed position in which the strips clamp the display material along the edges thereof, the strips in the latter position also serving as the face of the frame. Similar frames constructed of extruded plastic strips are disclosed in U.S. Pat. Nos. 4,512,094, Seely, and 4,519,152, Seely et al.
The prior art clamping type frames, as exemplified by the above identified patents, employ relatively complex hinge configurations and biasing spring arrangements. As a result, such frames are expensive to manufacture and may malfunction, particularly after repeated use.
It is the primary object of the present invention to provide an elongated clamp suitable for use in a clamping type frame or other sheet holder which is of single piece construction, suitable for forming by injection molding techniques.
It is a further object of the present invention to provide such an elongated clamp which includes hinge and biasing configurations of simple and reliable design.
It is also an object of the present invention to provide such an elongated clamp member which may readily be provided with a wide range of surface ornamentations, thereby providing a frame or the like of attractive appearance.